1. Field of the Invention
The present invention relates to an apparatus and method for recording data and/or reproducing data from an optical recording medium, and more particularly, to an apparatus and method for adjusting a tilt occurring due to the inclination of an optical recording medium.
2. Description of the Related Art
An optical pickup unit must be perpendicular to a recording surface of an optical recording medium to effectively read signals from the optical recording medium. However, the optical recording medium may angle, or incline, when manufacturing and using the same. Thus, a tilt adjusting apparatus should be adopted to prevent such a tilt with respect to the optical recording medium.
Such a tilt adjusting apparatus is disclosed in U.S. Pat. No. 6,005,836.
FIG. 1 is a block diagram showing the structure of a conventional tilt adjusting apparatus. Referring to FIG. 1, a digital signal processor (DSP) 100 outputs a focus output drive (FOD) signal to a drive integrated circuit (IC) 101, so that an optical pickup 102 precisely focuses a light spot on a recording surface of an optical recording medium (not shown) at a predetermined distance from the recording surface. The drive IC 101 generates and outputs positive and negative FOD signals to adjust a tilt with respect to the optical recording medium. Here, the positive and negative FOD signals are generated so that the optical pickup 102 moves according to directions of current flowing through coils (not shown) inside the optical pickup 102 so as to keep the predetermined distance from the optical recording medium and the optical pickup 102.
In the conventional tilt adjusting apparatus, the optical pickup 102 only moves up and down. Thus, when the optical recording medium angles, or inclines, a laser diode (not shown) of the optical pickup 102 cannot be perpendicular to the recording surface of the optical recording medium. Accordingly, since aberration occurs due to the angling, or inclination of the optical recording medium, the optical pickup 102 cannot properly pick up data (i.e., record or reproduce) from the optical recording medium.